A switch is not a pants on type of corporal punishment implement. Unless the kid was wearing something like linen pants or the switch itself was fairly thick (making it more of a rod). Those marks are pretty severe for a switch, especially for them being a couple of days old. You don't have to put a lot of force behind a switch for it to hurt like hell. Like I said before, the worst whippings I ever had were from one, and they were from my mom. You don't have to put any arm strength into using one, just wrist action. If a man his size was drawing back and swinging with his arm, then that's more than should be inflicted on any kid, much less a 4 year old. He should have used a belt or better yet his hand, so he could guage just how hard he was hitting him.